1. Field of the Invention
The present invention relates to an electrical connection box suitable to be mounted on a vehicle, such as an automobile.
2. Description of the Related Art
FIG. 6 shows one known form of an electrical connection box of a vehicle. Electrical parts 32, such as relays, are mounted on an upper surface of a substrate in a junction block 31. A lower casing or cover 33 for the junction block 31 is fitted on the junction block 31 from below. The lower cover 33 accommodates connectors 34 connected to the end of a wire harness not shown in FIG. 6. The wire harness passes out of the lower cover 33 through an aperture (not shown) in the lower cover. Columnar projections 35 for temporarily locking the connectors 34 to the lower cover 33 project up from the base of the lower cover 33. Approximately cross-shaped temporary locking holes 36 into which the projections 35 can be inserted are formed in the base of lower covers 37 that are fitted on a lower side of the connectors 34.
When assembling the electrical connection box of FIG. 6, initially the lower covers 37 are fitted on the connectors 34. Then the projections 35 are inserted into the temporary locking holes 36 of the covers 37 to temporarily lock the connectors 34 to the base of the lower cover 33. Then, with the lower cover 33 fitted on the junction block 31, bolts. 38 inserted through the junction block 31 into complementary screwthreads of the connectors 34 are tightened. As a result, the connectors 34 are brought up to the junction block 31 and fixed in position on the junction block 31, so that, terminals of the components 32 engage terminals in the connectors 34.
However, in this construction, the gap between the connectors 34 and the lower covers 37 is large. Therefore, vibration causes both the connectors 34 and the lower cover 37 to be loosened and to shake. Consequently, noise is apt to be generated.
Further, because the lower cover 37 is, required in assembling the electrical connection box, a large number of component parts are required. Thus, the manufacturing cost of the electrical connection box is high.
GB-A-2338355 shows an electrical connection box similar to that of FIG. 6, in which a flotation, bracket, which is lockable into position on the lower cover, is provided inside the lower cover. The bracket receives the connectors from below, for initial positioning of the connectors.
Accordingly, it is an object of the present invention to provide an electrical connection box that has a construction which does not generate noise easily and can be made at low cost.
According to the present invention, there is provided an electrical connection box that includes:
(i) a substrate that carries electrical components and has a plurality of electrical terminals,
(ii) a molded synthetic resin casing adapted to be fitted on the substrate at the lower side thereof,
(iii) at least one connector that is receivable in the casing and mountable at a predetermined position on the substrate and has a plurality of electrical terminals engageable with said electrical terminals, of the substrate when the connector is brought to its predetermined position,
(iv) at least one fastener inserted in the substrate and engageable with the at least one connector and operable to draw the at least one connector to the predetermined position, and
(v) at least one holder for the connector that is molded in one piece with the casing and is open at its upper side to receive the connector.
In the electrical connection box, the connector(s) and the holder(s) have respective holding elements which are mutually engageable to hold the connector(s) in the holder(s), prior to the operation of the fastener to draw the connector to its predetermined position, whereby the fastener(s) through the connector(s) holds the casing at its fitted position on the substrate.
Preferably, the holder is constituted by at least two upstanding walls in the casing and the holding elements include mutually abutting projections on mutually opposed surfaces of the connector and the upstanding walls.
Preferably, the holding element of each upstanding wall has a cantilever arm projecting downwardly and integrally connected at its upper end with the side wall. This projection is preferably at the lower free end of the cantilever arm.
In the present invention, the connector is first engaged by the holder by insertion from above. The holder is integral with the casing, so that loosening of the connector from the casing is prevented. No additional part, such as the lower cover 37 of FIG. 6, is required in temporarily fixing the connector to the casing. Thus, the electrical connection box requires a smaller number of component parts than the known electrical connection box, and the manufacturing cost is reduced. The operation of the fastener, e.g. a bolt, draws both the connector and the casing into position, and holds them in the final position, so that loosening of the parts is minimized. Thus, noise is not generated in use.
In the present invention, each holder is preferably integral with the casing. In particular, the holding element of each holder is integral, so that the provision of the holder(s) does not increase the number of component parts. Thus the electrical connection box can be produced at a low cost.
It is easy to assemble the electrical connection box.
In this specification and claims, the directional terms xe2x80x9cupperxe2x80x9d, xe2x80x9clowerxe2x80x9d etc. are used for convenience and clarity of description, and are not intended to limit the invention. The electrical connection box of the invention may be assembled and used in any appropriate orientation.